Anti-Sleep (macOS caffeinate)

Use the bundled launcher from this skill directory. It creates a one-shot user LaunchAgent using only built-in macOS tools.

Required workflow

Never launch caffeinate with raw &, nohup, disown, or launchctl submit. Temporary execution shells can kill their descendants, and launchctl submit can restart a timed job.

Resolve scripts/anti-sleep.sh relative to this SKILL.md; never assume the user's current directory. Run:

1. Inspect current state:

scripts/anti-sleep.sh status

2. If status reports an active session and the user requested a new duration, automatically stop the old session. Never ask for confirmation.

scripts/anti-sleep.sh stop

3. Start the new timer for the requested duration:

scripts/anti-sleep.sh start 10800    # 3 hours

For a specific process, use start-pid. Apply the same automatic replacement rule if another session is active.

scripts/anti-sleep.sh start-pid <PID>

4. In a separate tool/shell call after the start command has returned, verify:

scripts/anti-sleep.sh verify

Only report success when verification returns STATUS=running and ASSERTIONS=active. Confirm the PID, flags, and wall-clock expiry. If verification fails, run stop and do not claim the Mac is protected.

Assertion flags

The default is -d -i: keep the display on and prevent idle system sleep. Pass explicit flags after the duration or PID when needed:

Flags	Effect
-i	Prevent idle system sleep; display may dim
-d	Prevent display sleep
-d -i -s	Also prevent system sleep while on AC power

Example:

scripts/anti-sleep.sh start 10800 -i

Status and stop

scripts/anti-sleep.sh status
scripts/anti-sleep.sh stop

The launcher tracks one exact LaunchAgent label, PID, start time, and expiry under ~/Library/Caches. It never uses broad pkill.

Fallback

If launchctl bootstrap fails, use a visible persistent terminal or cmux pane. Read the cmux skill before interacting with cmux. If no persistent surface is available, tell the user instead of starting an unreliable background job.

caffeinate cannot keep the keyboard backlight on. That setting is manual: System Settings → Keyboard → “Turn keyboard backlight off after inactivity” → Never.